Sarah Horsley told The Sunday Telegraph she asked Netflix not to dramatise the 1988 disaster at Klosters, Switzerland.
Major Hugh Lindsay was a friend of the prince and a former Queen's equerry.
Mrs Horsley said: "I was horrified when I was told [the episode] was happening and was very concerned about the impact on my daughter."
She continued: "I'm very upset by it and I'm dreading people seeing it.
"I wrote to them asking them not to do it, not to use the accident.
